Method of making scissors



March 26, 1968 A. EIZENBERG METHOD OF MAKING SCISSORS Z5 Sheets-Sheet 1Filed Oct 22, 1965 H m m E V m ATTORNEY March 26, 1968 A. EIZENB'ERG3,374,694

METHOD OF MAKING SCISSORS Filed Oct. 22, 1965 I5 Sheets-Sheet 2 FIG. 2.

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ATTORNEY March 26, 1968 A. EIZENBERG 3,374,694

METHOD OF MAKING SCISSORS Filed Oct. 22, 1965 5 Sheets-Sheet .5

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l/V VE/V TOR Ali/WM? [UH/5M6 ATTORNEY United States Patent ()fiiceABSTRACT OF THE DISCLOSURE A method of making a pair of disposablesuture scissors from wire stock. This method includes coining a bladesection and forming a finger loop section in a piece of wire,

trimming the coined blade section to form a sharp burr,

and restriking a face of this blade to make this sharp burr flush withthe blade face. Finally, the scissor members are plated and assembled togive a pair of disposable suture scissors in which grinding is notnecessary to create sharp cutting edges. A

This invention relates to an improved medical scissors particularlyadapted to cut sutures, gauze, bandages, and also to a method of makingthese scissors from wire stock.

Previously, hospital and medical scissors were hand made, requiringintricate hand fitting, bending, and grinding to get a particular pairof scissors to cut properly. All of this hand work on the scissors,which were usually of a very expensive grade of stainless steel, madethem very expensive. Therefore, they could not economically be discardedafter a single use but had to be rewashed, resterilized and used againseveral times.

Inexpensive scissors have been made in the past but these were generallyalong the lines of toy paper cutting scissors and did not have sharpcutting edges that were reliable for medical uses.

The purpose of this invention is to provide an improved hospital andmedical scissors that has reliable sharp cutting edges and which can beeconomically discarded after a single use. This one-time use avoids anypossibility of cross-contamination between patients.

It is an object of this invention to provide an improved scissors forhospital and medical use with reliable sharp cutting edges. I

Another object of this invention is to provide a tubular spring biasedfastening means for urging two scissor halves together with proper forcedespite variances in thickness of the scissors. I i

It is another object of this invention to provide a method of making ahospital and medical scissors from wire, which scissors have reliablesharp "cutting edges.

Still another object of this invention is to provide a disposable suturescissors with blades adapted to be coined from a common coining die.

Other objects of my invention will become apparent upon furtherexplanation with reference to the following drawings, in which:

FIGURE 1 is a top plan View of the scissors of my invention;

FIGURES 2 through 7 show the various steps of the process for makingeach scissor member from wire stock;

FIGURE 8 is a section taken along line 8-8 of FIG- URE 1;

FIGURE 9 is a section taken along line 99 of FIG- URE 1;

FIGURE 10 is a sectional view taken along line 10-- 10 of FIGURE 1;

FIGURE 11 is an enlarged fragmentary View of the scissor blades of myinvention showing them cutting a suture;

FIGURE 12 is an enlarged fragmentary view of scissor blades ofunreliable suture scissors showing why they do not always out thesuture; and

3,374,694 Patented Mar. 26, 1968 FIGURE 13 is a fragmentary sectionalview of a scissor blade showing my novel cutting burr.

Referring to the drawings, the same numerals are used throughout torepresent the same element in the various views. The assembled pair ofscissors shown in FIGURE 1 comprises two members 21 and 22'pivotallymounted together by pivot means 4. These members terminate at one end infinger loops 31 and 32 and terminate at an opposite end in blades 41 and42. For removing sutures a notch 8 is provided in one of the blades tobook under a suture to pull it taut for cutting.

FIGURE 8 shows a cross-section through the scissor blades as they arecutting. Blades 41 and 42 have cutting faces 51 and 52 which are opposedto each other when the scissors are closed. However, it should berealized that scissors in order to cut properly have a slight inward bowin their cutting blades from their pivot point to the tip ends 71 and72. This is to assure that each blade will be forced against the otheras the scissor blades are closed. Thus, there would be a slight gapbetween the cutting 'faces 51 and 52 intermediate this pivot point andtip ends 71 and 72 when the scissors were completely closed.

Cutting edges 81 and 82 are substantially perpendicular to and intersectcutting faces 51 and 52. At these intersections are cutting burrs 61 and62 which are extensions of cutting faces 51 and 52 being flush with themand extending .0002 to .004 inch laterally outwardly as sharpoverhanging ledges from cutting edges 81 and 82. On an exterior of eachblade is a plating 17 sufiiciently thin to follow the contour of cuttingburrs 61 and 62 leaving them sharp and knife-like. This plating 17 isfrom .0001 to .0003 inchthick and its configuration around cutting burrs61 and 62 is best shown in the enlarged view of FIGURE 13.

In very inexpensive scissors the fastening means is a critical elementand often holds the two blade-s together either too tightly or tooloosely. I have overcome this disadvantage by providing a spring actionin the fastening means as shown in FIGURE 10. Fastening means 4 includesa thin tubular portion 13 which extends through the pivot holes in eachblade. At the ends of the tubular portion 13 are annular spring sections14 which outwardly fold over to .form a skirt 15 pressing against blades41 and 42. The spring portions 14 exert a spring force on skirts 15,urging them against the two blades. Thus, the blades are held underproper tension even though in production these blades may vary inthickness.

The method of making the novel scissors of FIGURE 1 from wire is shownin the sequence of steps in FIG- URES 2-7. Since members 21 and 22 aremade in identically the same way except for suture notch 8, the steps inmaking these members will be described relative to just one member, i.e.member 22. First a finger loop 32 is formed in one end of a length ofwire and an offset portion 5 is formed at an opposite end. Olfsetportion 5 insures the metal in the blade section will properly flow intothe blade form as shown in FIGURE 3. The blade is then coined to a shapeas shown in FIGURE 3, leaving a thin metal portion 6 about the peripheryof the blade. This peripheral metal portion 6 is trimmed olf as shown inFIGURE 6 by a shearing action that proceeds from a back of the bladetoward the cutting face 51 perpendicularly to cutting face 51. Duringthis step a pivot hole 7 is also punched, leaving member 22 in the formas shown in FIGURE 4.

Next, a suture notch is punched in one half of the members if a suturescissors is desired, leaving a member 22 as shown in FIGURE 5.Preferably, this cupshaped suture notch is defined by a surface 16forming an acute angle a between 70 and 85 with the cutting face 52, asshown in FIGURE 9. This surface 16 is formed by punching out a chunk ofmetal at an angle to cutting face 52 to form notch 8.

The formed member 22 in FIGURE (and also member 21) is then subjected toa restrike operation as shown in FIGURE 7 to force cutting burr 62 intoa configuration shown in FIGURE 8. Now cutting burr 62 is flush withcutting face 52 and extends as a sharp overhanging ledge from cuttingedge 82. In the previous step of shearing off the metal portion 6perpendicularly to and in a direction from the back of the blade towardthe cutting face 52, the cutting burr 62 was forced to protrude from theplane of cutting face 52. Such burrs overlap and grind against eachother, flaking off as the scissors were closed. To overcome this, therestrike step forms the cutting burr 62 flush with cutting face 52. Therestrike step of FIG- URE 7 is carried out by fitting the blade 52 in adie con forming precisely to the back surface of the blade and even tothe slight inward bow of the blade from its pivot hole to its tip 72.The restrike means 91 has a surface 29 corresponding to the surface ofcutting face 52 and upon the impact of surface 29 against cutting face52, burr 62 is formed as in FIGURE/13.

After restriking, members 21 and 22 are plated with a V platingsufliciently thin to follow the contour of cutting burrs 61 and 62, asshown in FIGURE 13. The members 21 and 22 are next assembled by pivotmeans 4. Now the cutting burrs 61 and 62 themselves form very sharpknife-like edges which shear against each other to cut and no expensivegrinding operation is needed to insure this.

FIGURE 11 is an enlarged view of the tips of the cutting blades 41 and42 showing how these two blades cut a suture 95 in suture notch 8. Thescissors have two convex cutting edges 81 and 82 engaging each other tocut continuously and progressively toward the blade tips as the scissorsclose. As shown in FIGURE 11, the two blades 41 and 42 always meet at aV even in suture notch 8 to slice 01f suture 95.

The relationship between the two blades shown in FIG- URE'll gives aclean smooth cut to the suture and I have found it to be far superiorthan the relationship in some previous suture scissors as shown inFIGURE 12. Here in FIGURE 12 the suture 96 can get into a pocket in thesuture notch 98. As shown by dotted lines, the two blade tips canoverlap before suture 96 is cut. As

' is usually the case, the blades are slightly bowed inwardly towardstheir tip to insure that each blade will be urged against the other atthe tip. When the two tips engage and overlap, as shown in FIGURE 12,this springs the blades slightly apart at the suture notch, and suture96 is merely kinked and slips between the two blades without being cut.Such does not happen in my suture scissors in FIGURE 11 because thesuture 95 must be out before the blade tips can overlap.

Another feature of the scissor blade tips is also shown in FIGURE 11.This is the configuration of the blades 41 and 42 that allows each bladeto be coined from a piece of wire into the blade shape in a commoncoining die. In the past, each blade of a suture scissors had differentand individual contours in addition to the suture notch.

I have found that a scissor blade with convex cutting edges 81 and 82adjacent the blade tips will give excellent cutting results across aconcave suture notch 8 in one of the blades near its tip. Since both ofthese blades in FIGURE 11 are identical except for the suture notch,they can be coined in a common die, thus greatly reducing themanufacturing costs and sorting and control problems.

In the foregoing specification I have used specific examples to describemy novel disposable medical scissors and the method for making them. Itis understood that persons skilled in the art can make modifications tothese specific examples without dep rting f Otn t Spirit and scope ofthis invention. V

I I claim:

1. A method of making disposable medical scissors of wire comprising:making each of a plurality of scissor members by forming in a length ofwire a finger loop at one end and an offset kink at an opposite end;coining a scissor blade from the offset portion of the wire length,leaving a thin portion of metal extending outwardly about the peripheryof the face; removing the thin metal portion from the periphery bysevering it perpendicularly to the blade face and in the direction froma back of the blade toward the blade face, thereby leaving a small burrabout the blade face periphery protruding through a plane of the bladeface; deforming the burr into the same plane of the blade face byrestriking the blade face with means having a surface corresponding tothe blade face, thereby forcing the cutting burr into a laterallyextending sharp ledge flush with the blade face; forming a pivot hole ineach blade; and assembling two members together by pivot means, wherebythe cutting burrs shear against each other to cut as the blades arepivoted about said pivot element. V

2. A method of making disposable medical scissors of wire comprising:making each of a plurality of scissor members by forming in a length ofwire a finger loop at one end and an offset kink at'an opposite end;coining a scissor blade from the offset portion of the wire length,leaving a thin portion of metal extending outwardly about a periphery ofa face of the blade; removing the thin metal portion from the peripheryby severing the blade face; forming a pivot hole in each blade; plat- 7ing the members with a plating sufiiciently thin to follow the burrcontour; and assembling two members at their pivot holes by a pivotmeans whereby the cutting burrs shear against each other to cut as theblades are pivoted about said pivot element.

3. A method of making disposable medical scissors from wire as set forthin claim 1 wherein the deforming step leaves a cutting burr that extendslaterally between .0002 and .004 inch. j

4. In a method of making a scissor blade for a disposable medicalscissors the improvement of: coining an end portion of a length of wireinto a blade having a face with a thin portion of metal extendingoutwardly about the periphery of the face; removing the thin metalportion from the periphery by severing it perpendicularly to the faceand in the direction from a back of the blade toward the blade face togive a small burr about the blade face periphery protruding through aplane of the blade face; and deforming the burr into the same plane ofthe blade face by restriking the blade face with means having a surfacecorresponding to the blade face, thereby forcing the cutting burr into asmall laterally extending sharp ledge which is flush with the bladeface, said laterally extending sharp ledge adapted to engage a similarledge of another scissor blade in a shearing action.

5. A method of making suture scissors comprising: making first andsecond scissor members by forming in each of two lengths of metal wire afinger loop at one end a and an offset portion at an opposite end;coining a scisfirst scissor member, both of the blades adapted to becoined from a common coining die; removing the thin metal portion fromthe periphery of each blade by severing it perpendicularly to the bladeface and in a direction from a back of the blade toward the blade face,thereby leaving a small burr about the blade periphery protrudingthrough a plane of the blade face; cutting a concave suture notch in oneof the blades near its tip; deforming the burr of each blade into thesame plane as the blade face by restriking the blade face with meanshaving a surface corresponding to the blade face, thereby forcing theburr into a laterally extending sharp ledge flush with the blade face;and pivotally fastening the two blades together so the convex cuttingedges will engage each other to cut continuously and progressivelyforward across the concave suture notch toward the tips of the scissorblades as these blades close.

References Cited UNITED STATES PATENTS 1,565,340 12/1925 Treiber 761041,768,462 6/1930 Dixon et al. 76-104 1,900,413 8/1933 Carpenter 76-104

